1. A green swimming pool where the water is literally green. This pool has an algae infestation. It is a gross, green body of water that no one wants to swim in. It is a big mess that will require a lot of work, chemicals and time to clean up. This pool may smell bad and, worst of all, is a safety hazard and liability. If your pool water is green and you are not going to do anything about it, that tells me that you no longer want a swimming pool. Please drain it.
2. A green swimming pool that is energy efficient. This green pool is low energy use, low chemical use, and low waste. It is a swimming pool that is easy to maintain, crystal clear and ready to swim in and enjoy every day. In this case "green" is a good thing. As a professional pool builder, the only pool that I want to build, and the only pool that you should want to have built, is a clean and green pool. This type of green pool is the real topic here!
Clear Pool Water - Do I Have to Run My Pump 24 Hours Per Day?
For many years I have advocated installing 2-speed pumps and, as they became available, variable speed pumps in residential swimming pools. These pumps will circulate water 24/7 for less than the cost of running a single speed pump for 10 hours per day and you will benefit from the constant circulation. More water passes through the filter which, in turn, sends more clean water back into the pool. As a result of this constant dilution, your pool stays crystal clear. People often ask, "Do I have to run my pool 24/7?" The answer is no, your pool pump does not have to run constantly. However, there are benefits to doing just that. It is also possible to run your pool pump constantly while consuming less energy than ever before.How Does Circulating the Water in My Pool Keep it Clean?
Here is a simple test you can do at your kitchen table to demonstrate this concept. Take 6 or 7 clear glasses. Fill #1 with dirty water, fill the rest halfway with clean water. Then pour half the dirty water into glass #2. Continue this process, pouring about one half the water from each glass as you go down the line into the next 5 or 6 glasses until you get to the last glass. The water in the last glass should be pretty clear.Clean Pool Water - Show Me the Math
In a swimming pool a turnover is considered to be the equal amount of the entire volume of water in the pool running through the filtration system one time. Remember, as water is being introduced to the pool it is mixing with the rest of the full body of water, so not every single molecule of water will have passed through the filtration system. Here is some simple math for illustration purposes.An average play pool in Phoenix, Arizona is about 12,000 gallons. If a pool pump can produce 100 gallons of flow (a typical 1-1/2 hp pool pump) in each 60 minutes it will send 6,000 gallons of water through the filter and back out into the pool. This filtered water dilutes into the existing water and each consecutive turnover gets the pool water a little cleaner, just like the glass example mentioned above. This is how it works.
Turnover #1 63% 2 hours (2 x 6,000 per hour = 12,000 gallons)
Turnover #2 86% 4 hours (4 x 6,000 per hour = 24,000 gallons)
Turnover #3 95% 6 hours (6 x 6,000 per hour = 36,000 gallons)
Turnover #4 98% 8 hours (8 x 6,000 per hour = 48,000 gallons)
Turnover #5 99.3% 10 hours (10 x 6,000 per hour = 60,000 gallons)
The above example is a perfect single speed setup and assuming good flow rates. Keep in mind that undersized plumbing, poorly plumbed pools and/or oversized pool pumps may negatively impact flow rates.
Now, let's take a look at a 2-speed pump example running the pump in high for 4 hours and low for 20 hours.
High speed runs at 1-1/2 HP and uses full power (cleaning mode):
Turnover #1 63% 2 hours (2 x 6,000 per hour = 12,000 gallons)
Turnover #2 86% 4 hours (4 x 6,000 per hour = 24,000 gallons)
Low speed runs at 1/3 HP and uses about 1/6th the electricity (circulation mode):
Turnovers #3 thru #10 95% - 99.9% 20 hours (20 x 3,000 per hour = 84,000 gallons)
Note: A variable speed pump will do even better than this because it has the ability to be tuned and run in other speeds. Keep in mind you do not have to run 24/7 to benefit from this.
The bottom line is
- you use less electricity
- you get more turnovers
- the pool is always filtering and introducing clean water back to the pool
- the dilution principle is constant
Does a Skimmer Really Help?
An average pool in Phoenix will attract 20 to 30 lbs of dust every year. Everything enters the pool at the surface, so if you have a great and efficient circulation system and your skimmer is in the right spot in the pool, this debris, dirt and organic material will be skimmed and filtered long before it presents a problem at the bottom of the pool.How Does Better Circulation Save Money?
Water moving nearly all the time will result in a better mix of chemicals and temperature, both of which affect water chemistry and, ultimately, water clarity. If the water is more evenly and consistently mixed the pool will need less chlorine to stay sanitized and it will cost less to heat or cool. This saves you money!There are many costs associated with pool ownership -- initial costs, maintenance costs, energy costs, chemical and sanitation costs and so on. The cheapest pool in the beginning will cost you a fortune in the long run and you will likely be sorry you ever built it once you get beyond the initial euphoria and excitement. The difference between a low maintenance, low energy, low chemical and low waste pool is at most 10 to 15% in initial cost, an amount you will get back in ROI (return on investment) in a couple of years. Don't be foolish and listen to sales people only interested in making a sale and commission; they won't be maintaining your pool or paying your energy bills down the road.
